Avelox and Neuropathy

Avelox is one of the most commonly prescribed antibiotics in the United States resulting in millions of dollars of annual sales. Unfortunately, the drug has been linked to a very serious condition called peripheral neuropathy. Peripheral neuropathy is often permanent and can be characterized by muscle weakness, numbness, and pain. Recent evidence has revealed that Avelox’s manufacturers, Bayer and Merck, knew about this condition for many years and yet failed to warn patients and physicians. We are rapidly learning more about the connection between Avelox and neuropathy and it is leading to lawsuits. If you believe you have a potential claim, call us at 800-553-8082 or get for a free online consultation.

Avelox History

Avelox was approved by the United States Food and Drug Administration (“FDA”) on December 10, 1999. It is the brand name for the drug moxifloxacin, a fourth-generation synthetic fluoroquinolone antibiotic. Avelox is manufactured by Bayer Healthcare Pharmaceuticals, Inc. and distributed and marketed by Merck and Co., Inc. and McKesson Corporation. Today, Avelox is sold in over 80 countries worldwide and is available as an oral tablet, IV solution, or ophthalmic solution.

Bayer submitted a New Drug Application to the FDA for Avelox on December 9, 1998. With the patent for Bayer’s other major antibiotic, Cirpo, set to expire in 2003, Bayer needed an heir apparent to compete with other third and fourth generation flouroquinolones, such as Levaquin. Avelox was considered the best contender. Avelox is effective at treating gram-negative and gram-positive bacteria such as Escherichia Coli (E. choli) and Streptococcus Pneumoniae. It works by interfering with bacterial DNA gyrase. During this process, the drug binds to certain enzymes, preventing DNA replication.

Unfortunately, despite these positive benefits, the drug also interacts with a variety of different receptors in the central nervous system (including GABAa receptors). GABAa receptors are found throughout the central nervous system. When activated, GABAa receptors cause hyperpolarization of the neurons, inhibiting neurotransmission of critical information. The net effect is that a patient begins experiencing peripheral neuropathy, a condition characterized by pain, burning, tingling, numbness, weakness, sensitivity, and lack of neuromuscular coordination. This condition often appears very quickly after taking Avelox and may last for an indefinite period of time. In many cases, the condition may be permanent.

Avelox Label Warnings

Fluoroquinolones have a long history of causing serious side effects. As a result, the FDA has removed many of these drugs from the market. For example, in June 1992 the FDA removed Omniflox (temafloxcin) from the market due to concerns the drug caused low blood sugar, kidney failure, and anemia. Seven years later the FDA removed Trovan (Trovafloxcin) from the market due to severe liver toxicity.

When Avelox was first manufactured and submitted for approval, there was a plethora of research raising concerns about the drug causing peripheral neuropathy. Despite Bayer advertising on its website that Avelox is “safe and effective” and “has a well-characterized safety profile, which has been studied in over 14,000 patients in clinical trials and 92,000 patients in post marketing surveillance studies,” the reality is that as early as 1992 Bayer knew there was an association between fluoroquinolones and peripheral neuropathy.

For example, in 1992 Dr. Aoun from the Infectious Disease Clinic and Microbiology Laboratory at the Institute Jules Bordet in Belgium wrote a letter to the editors of Lancet expressing significant concerns about the association between fluoroquinolones and peripheral neuropathy. A similar article entitled, “Peripheral Sensory Disturbances Related to Treatment with Fluoroquinolones,” was published by Karen Hendenmalm and Olav Spigset in 1996.

In 2001, Jay S. Cohen published a research study in the United States entitled “Peripheral Neuropathy Associated with Fluoroquinolones.” This study followed forty-five patients and expressed concerns over the link between permanent peripheral neuropathy and drugs such as Avelox.

In 2002 and 2003, Bayer was informed by the FDA of numerous submissions to the FDA’s Adverse Event Reporting System indicating a causal link between Avelox and peripheral neuropathy. Perhaps more concerning was that many of the reported adverse events were said to be permanent.

In response, Bayer changed the Avelox label in September 2004 but only included the following minor changes:

Peripheral Neuropathy: Rare cases of sensory and sensorimotor axonal polyneuropathy affecting small and/or large axons resulting in paresthesias, hypoesthesias, dysesthesias and weakness have been reported in patients receiving quinolones.

As you can see from the above, Bayer’s new label misrepresented the significance of the causal link between Avelox and peripheral neuropathy. Not only did the label fail to mention that the condition was often permanent, it also said it only occurred in “rare cases,” a statement that simply was not true based upon the research and reported adverse events.

Moreover, despite changing its label, Bayer, Merck, and its distributor McKesson, failed to send a “Dear Doctor” letter to physicians warning them about the link between Avelox and peripheral neuropathy. Meanwhile, Bayer, Merck, and McKesson continued to market and promote the drug as if it had an impeccable safety record.

Finally, in 2013, the FDA stepped in and said these warnings were simply inadequate. On August 15, 2013, an updated warning was issued in which the FDA required Bayer, Merck, and McKesson to state clearly on its labels that Avelox was associated with the rapid onset of permanent peripheral neuropathy. The updated warning also removed the statement that nerve damage only occurred in “rare cases.”

Unfortunately, for many individuals these changes came too late. Many doctors have been prescribing Avelox for years, and for many patients, the effects of Avelox have become long-lasting and permanent.

Fortunately, some patients have decided to fight back, filing lawsuits against the manufacturers of Avelox in federal court alleging failure to warn, negligence, breach of express warranty, breach of implied warranty, fraud, negligent misrepresentation, fraudulent concealment, strict liability, violation of consumer protection laws, and negligent infliction of emotional distress. Many of these lawsuits are seeking both compensatory and punitive damages. It should be noted that these kinds of lawsuits can be complicated and should only be handled by an experienced personal injury attorney.

Getting Help from a Lawyer

These cases are new. There is still a lot to learn about what happened and what Merck and Bayer knew about Avelox and neuropathy. But we believe these will be viable claims. If you or a loved one has been seriously hurt or killed by taking the drug Avelox, you want answers and you want to be compensated for the harm that was done. Call us at 800-553-8082 or get for a free online consultation.